Please post the output from "mount", using code tags as DM asked. I suspect the first is caused by a filesystem that doesn't support permissions, like FAT, while the second sounds like the filesystem is mounted read-only, make an NTFS filesystem mounted using the kernel driver.

"Insanity: doing the same thing over and over again and expecting different results." (Albert Einstein)

mount shows nothing mounted on /mnt/share[12] but your fstab listing confirms what I suspected about the filesystems. You cannot change ownership on a FAT filesystem, it has no concept of ownership.

The in-kernel NTFS driver only allows reading by default, writing is disabled for a very good reason - it breaks things. The solution is to blacklist the ntfs module and install ntfs-3g, a FUSE filesystem that does support reliable writing.

A better solution, as you are running a Linux file server, is to use proper Linux filesystems like ext4 instead of trying to shoehorn in alien choices. The only reason for using these filesystems would be if you want to be able to unplug the drivers from the file server and connect them directly to a Window box, which rather misses the point of a file server.

"Insanity: doing the same thing over and over again and expecting different results." (Albert Einstein)

I will take your advice and reformat the NTFS one to ext4 once I've found somewhere to copy the files already on that device.

Meanwhile, I've sorted the 'mount' problem (I'd got the VFAT and NTFS formats the wrong way round in fstab, doh!) so I should now be able to share the VFAT drive using samba.

Can you help me with my samba problem too? I've installed the latest verson of samba (sudo apt-get install samba), when I try to run the smbpasswd command that Graham suggests, I get the response '-bash: smbpasswd: command not found'.

I've found the problem. Using 'sudo aptitude search' I got a listing of the installed packages in my Pi, and compared with the equivalent listing on my (Mint14) netbook. Lo and behold, the obvious difference was that the 'samba-common-bin' package was missing from my Pi.

So, I've done a 'sudo apt-get install samba-common-bin' on my Pi, and I can now run the 'smbpasswd' command.

Thought I'd provide this update, just in case anyone else is having the same difficulties